Hey I'm a guy who has second-guessed the team in our playoff defeats the last couple of years but this year we got the very best out of our boys and then some. After Brady went down, I thought we would go 10-6 if everything fell into place (Cassel not imploding, D stepping up). We did one game better, albeit under different circumstances (Cassel stepping up to save an imploding D).
If by defense imploding, you mean the defense having to field 2 LBers who were out of work for much of the season as starters to make it through the remainder of the season, then I can agree with you.
This defense lost the following to the IR:
Rodney Harrison - Starting Safety
Tank Williams - Reserve Safety
Terence Wheatley - Rookie CB
Adalius Thomas - Starting OLB
Pierre Woods - Reserve OLB / Special teams star
Tedy Bruschi - Starting ILB (okay - he wasn't IRed, but he probably should have been)
Then, at various points in the season, they lost the following:
James Sanders, Lewis Sanders, Ty Warren, Richard Seymour, Jarvis Green, Gary Guyton.
But if you are referring to the defense being bad and acting like there is something more they could have done, we'll have to disagree.